The lawyer for Richard Colvin, a former senior diplomat with Canada's mission in Afghanistan, says the Conservative government seems to be retaliating for Colvin's testimony on prisoner torture by withholding payment of legal fees.

Richard Colvin, a former senior diplomat with Canada's mission in Afghanistan, appears before a House of Commons committee in Ottawa in November 2009. (CBC)In a letter sent Monday to the Military Police Complaints Commission, Colvin's lawyer, Owen Rees, says the government hasn't responded to fee payment requests since Colvin testified before the Commons special committee on Afghanistan in November and is "impeding" his ability to act as a witness in the commission's investigation.

A foreign affairs spokeswoman told CBC News in an email that two invoices submitted by Colvin's previous counsel for more than $21,000 have been paid. A third invoice, which has been received, is being reviewed and a decision will be made in the near future, Katherine Heath-Eves said.

Since Colvin changed counsel, he hasn't submitted an application for more funding, Heath-Eves said, Should one be sent, it will also be reviewed and a decision will be made, she said.

In his testimony, Colvin alleged that all detainees transferred by the Canadian military to Afghan prisons were likely tortured by Afghan officials. He also said his concerns were ignored by top government officials and charged the government may have tried to cover up the issue.

Colvin, as a federal civil servant summoned to speak to the committee, is entitled to legal coverage from the government.

Rees writes that by "failing to respond" to his client's request in late November for financial assistance, the government has put up "significant obstacles" to Colvin obtaining independent legal counsel and "obtaining the legal indemnification to which he is entitled as an employee of the Public Service of Canada."

"Coupled with the government’s public attacks on Mr. Colvin and his testimony ... our client is left with the reasonable belief that the denial of further legal indemnification is a reprisal for his participation before the committee and the commission," the letter states.

Prime Minister Stephen Harper has drawn fire for his decision to suspend Parliament until after the Vancouver Olympics, a move that critics contend was aimed at shutting down the committee's hearings and sidestepping opposition MPs' embarrassing questions over the detainee controversy.

The Military Police Complaints Commission's own investigation into detainee transfers has been effectively sidelined until the government appoints a new commissioner.

Colvin put in 'impossible position': Rae

Following the letter's publication in the news media, Liberal MP Bob Rae said the Conservatives have put a public servant in an "impossible position where he can't protect his legal rights."

"It's not the way to treat a public servant and someone like Colvin, who has had the courage to come forward," Rae said.

In the days and weeks following Colvin's appearance before the Afghanistan committee, Defence Minister Peter MacKay fiercely questioned the credibility of Colvin's testimony on Afghan prisoners and staunchly defended the government's handling of the issue.

MacKay also said the Conservatives would not try to remove Colvin from his current posting as a senior intelligence official at the Canadian Embassy in Washington.