VANCOUVER — The RCMP have confirmed investigators have opened a criminal investigation into former B.C. Conservative MP Gurmant Grewal's campaign donations.

"We're investigating the handling of the campaign contributions and donations," said Insp. Kevin DeBruyckere, of the RCMP commercial crime section.

DeBruyckere said Monday thousands of dollars may be involved, but he wouldn't reveal more about the police investigation, which comes after complaints from people who said they did not receive receipts for campaign contributions.

Grewal has been battered a series of controversies, including going public with secretly recorded audio tapes of then-Liberal health minister Ujjal Dosanjh.

Grewal said he was trying to catch Dosanjh offering him a job in exchange for his vote in the House of Commons.

The former Surrey MP took stress leave last summer, right around the same time police were speaking to people who claimed they made a campaign contribution to Grewal, but didn't get a tax receipt.

He did not run in January's federal election.

He could not be reached for comment Monday.

Vancouver businessman Barj Dhahan told The Canadian Press last July that he contributed $600 towards Grewal's campaign in December, 2003 and never received a tax receipt.

Police would only confirm then that they had launched an investigation after complaints from other people who had not received receipts for contributions they made to Grewal's campaign.

DeBruyckere would not say Monday if search warrants had been executed in the investigation.

But he confirmed police were approaching people with cheques they had written in connection to Grewal.

DeBruyckere said commercial crime investigations are generally lengthy and it may be a few more months before police decide whether to present their findings to Crown prosecutors.

From the police investigation Crown counsel will decide if charges should be laid.

Grewal became an MP in his suburban Surrey-area riding in 1997.

Just after the January election, the federal ethics commissioner cleared Dosanjh of allegations that he offered a reward to the Conservative MP in exchange for support during a crucial budget vote.

Bernard Shapiro instead took Grewal to task, calling his conduct "extremely inappropriate."