Winston Peters says the Financial Markets Authority must investigate "a huge volume" in trading of SkyCity shares.

The New Zealand First leader was discussing the Government's contentious pokies and convention centre deal with SkyCity when he raised allegations of improper trading.

Mr Peters told Radio New Zealand there was a huge volume of trading last Friday, and not any other day.

He said Parliament was told the revised convention centre design was agreed between the Government and SkyCity last Friday.


"There was behaviour which was simply unacceptable," Mr Peters told Morning Report.

He said he was lodging a complaint with the Financial Markets Authority today.

Economic Development Minister Steven Joyce said Mr Peters' suggestions of inappropriate trading were probably false.

"Anybody can ask, but I think he's just trying to make a story out of something," Mr Joyce told Newstalk ZB.

The minister said it was an issue for SkyCity and the FMA to discuss but the Government had not behaved inappropriately.

"We didn't go out there and talk to anybody," Mr Joyce said.

SkyCity refused to comment this morning.

Comment is being sought from the Financial Markets Authority.