Key Points:

Parliament's privileges committee is set to table its verdict on Winston Peters tonight - and it is expected to be divided down party lines.

The Committee and the Clerk of the House have confirmed if the committee's findings are to be debated in the House tomorrow as is anticipated, then they have to be officially tabled before midnight.

It remains up in the air as to whether the committee's report will be accessible this evening, as Parliament's bills office closes at 5pm - the same time as the privileges committee is due to finish its deliberations.

The tabling of the report follows New Zealand First's decision to lay a complaint with police over the Serious Fraud Office (SFO) giving evidence to a parliamentary inquiry.

NZPA understands party president George Groombridge laid the complaint at Masterton police station this morning.

Today's complaint alleged that SFO director Grant Liddell had acted illegally by supplying information to the privileges committee. The complaint accused him and other members of the SFO of abuse of statutory powers.

The committee has been looking into whether Mr Peters should have declared Mr Glenn's donation as a gift. Mr Peters has said he was unaware of the $100,000 donation to his legal fund until his lawyer alerted him to it in July.

The SFO is holding a separate inquiry into two other donations to NZ First.

Last Thursday, party leader Winston Peters said the SFO had exceeded its powers by giving evidence to Parliament's privileges committee.

Mr Peters argued section 39 of the Serious Fraud Act precluded the SFO's actions.

"What they've done is totally ultra vires (beyond its powers) and they've done it with malice in my view and I will set out to prove it."

Section 39 of the Act requires the SFO "to observe the strictest secrecy in relation to any information which is protected under any Act other than the Inland Revenue Department Act".

Information could only be disclosed internally within the SFO for investigating fraud or within the judicial system.

Earlier today Helen Clark said the privileges committee report on Owen Glenn's donation to New Zealand First was unlikely to lead to Winston Peters' reinstatement as Foreign Minister.

The committee sits for what is expected to be the final time today before releasing findings on the pecuniary interests complaint made against Mr Peters.

Mr Peters handed Helen Clark his foreign affairs, racing and associate senior citizens portfolios on August 29 after the SFO announced a separate investigation into the fate of donations to NZ First.

Asked on Newstalk ZB if Mr Peters could be brought back after the privileges committee tables its report, Helen Clark today said his suspension from ministerial duties looked likely to continue.

"I very much doubt there would be anything in [the report] that would justify reinstatement," she said.

The Prime Minister said the committee investigation had become politicised.

"This process has become so politicised, that it's clear that some MPs went into that committee having made up their mind before they had heard a single piece of evidence," she said.

"I think that members have to be very careful not to go beyond the evidence to draw conclusions which are fundamentally politically motivated."

Helen Clark said the process had been "tainted from the outset" and for that reason she was unlikely to be forced into a decision over Winston Peters this week.

But the Prime Minister's comments drew a swift response from the opposition.

John Key said it was ridiculous for Helen Clark to claim the committee's investigation into New Zealand First was tainted by politics.

Mr Key said the privileges committee would always be made up of politicians and there was not the slightest hint of politics interfering with its business.

The committee's chairman, National MP Simon Power had not discussed its investigation with him, he said.

Mr Key said Owen Glenn's evidence to the committee was backed up by documents and the people who have been changing their story were Winston Peters and his lawyer Brian Henry.

Meanwhile, the Serious Fraud Office (SFO) has reported progress as it continues investigations into New Zealand First's handling of political donations.

The SFO is investigating whether donations from Sir Robert Jones and the Vela Brothers reached New Zealand First as intended.

It has been three and a half weeks since the office announced the investigation and SFO director Grant Liddell's office, in an email, said the investigation was proceeding expeditiously.

However, the SFO is giving no timeline for when it might make an announcement about the outcome of its work.