He might be leaving his teenage years behind but Daniel Radcliffe is still playing the boy wizard as the Harry Potter films head into their darkest chapters yet. Helen Barlow reports

As Daniel Radcliffe enters a London hotel room he is talking on his mobile. When he puts it away he confides : "I'm such a terrible host. I invited a friend over for dinner tonight and because of all these interviews I've now told him to eat first!"

Radcliffe, who turns 20 in few weeks, is now definitely a young man. He may have performed those famous Equus nude scenes on stage partly to prove it, though he has long exhibited a certain maturity, the result of being on the set with some very interesting adults for most of his life. In interviews he never misses a beat, while on the set he is always generous and his co-workers have yet to dish on him.

Given the way many movie brats turn out - especially ones who are the undisputed stars of huge franchises (think Macaulay Culkin) - he has weathered childhood stardom remarkably well. What's more, he knows what he wants. When the final Harry Potter movies were about to be filmed he wanted them to be dark.

"My favourite stuff is always the dark stuff," he says. "When I read scripts for the first time that's what I always lean towards and it's what I want to see included - even more so in Harry Potter movies, because we need the films to appeal to adult audiences. In fact one of the things I was disappointed about with the sixth Harry Potter movie was that there wasn't so much of that element."

The film's director, David Yates, who came on board with the previous film, Harry Potter and the Order of the Phoenix, and who will remain with the franchise until its conclusion, was however quick to point out that Radcliffe will get his fill of darkness in the final two films, both based on J.K. Rowling's final book, Harry Potter and the Deathly Hallows.

"There's loads of darkness and not many laughs there, so David said it was best to give the audience as much comedy as we can while we can. There are huge opportunities for comedy in the sixth film and we use all of them, even though my natural inclination is not towards that. I love watching comedy but doing it is something else."

There are still three Harry Potter movies to come. Harry Potter and The Half-Blood Prince has long been completed - the release was delayed from November 08 to July 09. Harry Potter and the Deathly Hallows: Part I comes out in November 2010 with Part II following in July 2011.

"I'm very happy that the seventh book is being made as two films," notes Radcliffe, "because I was worried they would have to cut important scenes. For example in the fourth film you could cut out the house elf sub-plot and it doesn't affect the main story in any way. In the second film they cut out the Nearly Headless Nick Death Day Party. In fact that whole character has fallen by the wayside. The problem with doing that with the final book is that there is nothing that doesn't relate to the main story or drive it forward. There's not much you could cut. So we've given ourselves the room and opportunity to do it justice."

There's no doubting that the final films needed to be made with some speed, as the cast, particularly the slightly older and stockier Rupert Grint, are filling out more and more every day. It wasn't as if the films were hurried though. Radcliffe had one of his best experiences ever in the lead-up to filming The Half-Blood Prince, when he rehearsed lengthy scenes with Michael Gambon, who has played Hogwarts school principal Albus Dumbledore since the death of Richard Harris.

"I've always loved working with Mike, but I'd never had any big, in-depth scenes with him. It was exciting, knowing we were going to get a good run at those scenes. For the first four months it was just me and him, which was great. Actually when the rest of the cast finally came along, I thought, 'I don't like this'. I'd gotten so used to it being just me and Mike, who by the way is one of the best actors I've ever worked with, and probably the least professional. Which makes him an absolute joy to be around.

"He takes nothing seriously, is always having a laugh, yet somehow seems to turn it on the moment the cameras start rolling. Because of our lengthy time together it meant we had the chance to build up a great relationship off camera and hopefully that translated on to the screen."

In Harry's sixth year at Hogwarts he comes into the possession of a potions book that used to belong to the half-blood prince, and it contains some useful new spells and instructions on how to use them. Dumbledore meanwhile teaches Harry dark secrets about Voldemort (Ralph Fiennes), whose presence is looming over the proceedings. There's a new Hogwarts teacher, Horace Slughorn (Jim Broadbent), who proves useful for Harry, while Draco Malfoy (Tom Felton) seems to be sneaking around Hogwarts doing Voldemort's bidding.

Harry has been made captain of the quidditch team, Hermione is unhappy that Ron has a new girlfriend called Lavender (Jessica Cave), and romance is in the air for Harry as he finally realises his desire for Ginny Weasley (Bonnie Wright), Ron's sister.

Are they holding back slightly on the action to provide the big bang finale? "I don't think we're holding back, I'm giving my all on the set as I've been brought up to do," Radcliffe replies. "But it's true that this is very much a lead-in to the seventh instalment, it's setting up the final events, and that's why it might be a harder film to come to grips with. So that's why there are moments where we can be freer, we can have more jokes and a bit more fun with it. You don't always have to think about an immediate danger. Voldemort's not the main source of fear or evil; that's another character."

Radcliffe was more than ready for the romance. "By the time I made this film I'd done a nude scene on stage and a few kissing scenes, so I was totally blase," he says. "Poor Bonnie was very nervous. I hadn't factored that in. I'd taken it for granted that she'd be fine too. She'd never had to do that so I had to be calming with her and she did very well. Then of course you have Rupert and the carnal delights of his relationship with Lavender, which is very entertaining," he laughs.

You can't help but feel that as time has passed Radcliffe has moved further and further away from resembling his character.

"I'm probably more comfortable with my own company than Harry is," he admits. "I'm kind of okay to be alone and don't mind it. I've grown up with the support network of my parents, so I don't feel I'm ever properly on my own. There are people I can always talk to and Harry doesn't have that. That's why he feeds so much off the energy of his friends. When he's alone and having to face up to his own isolation it's even more terrifying for him."

One thing he shares with his character though is his rise to fame and becoming a target. "I find it very easy playing Harry when he's dealing with the attention he gets. I can relate to that, more than I can to death or being an orphan, because I have no experience of either of those. Though I've played an orphan three times now " (in December Boys, Equus and Harry Potter).

Radcliffe, who dropped out of high school a year early to appear on stage in Equus, says he has no need of a university education.

"I didn't want to go, it's as simple as that. I think most people go to establish their identity and what they want to do career-wise. I know what I want to do, more or less. Other people go to meet people from different backgrounds and that happens naturally on a film set. That's not to say I'm going to stop learning. I read a lot. I still have English lessons once a week, without the pressure of exams or essays. I have my own teacher and we basically chat about books and poems. In an ideal world that should be the way everyone learns. I don't fancy university in truth. I know exactly what I want to do - touch wood anyway."

Who: Daniel Radcliffe
Born: July 23, 1989, London
What: Harry Potter and the Half-Blood Prince
When: At cinemas from July 9