BP PLC's political action committee continues to raise funds from company employees in the wake of the Gulf of Mexico oil spill, although the oil giant has all but halted its campaign contributions to members of Congress.

A campaign finance report filed with the Federal Election Commission on Friday shows that the company has stopped virtually all contributions to lawmakers as it continues to grapple with the massive oil spill and its operations have come under heavy scrutiny on Capitol Hill. The PAC itself, however, has continued to receive contributions from BP employees, pulling in almost $20,000 during the month of May.

Those contributions to the PAC have come primarily in small amounts -- almost all are $50 or less -- from BP employees scattered across the country. The biggest single contributor during the last month was Lamar McKay, chairman and president of BP America, who made two separate contributions of $416.66.

Other contributors to BP's PAC included BP general manager for Federal and International Affairs Michael Brien, vice president for Government and Public Affairs Frank Hernandez and a number of other high-ranking officials and employees involved in BP's state-level operations. Each contributed no more than $250 in May and almost all are repeat contributors who have given hundreds of dollars to the PAC thus far this year.

Most of the BP's contributions from May -- about $11,470 of the $19,890 total -- came from individuals whose contributions for the year total less than $200, which means they do not have to be identified in the organization's Federal Election Commission filing.

All told, BP's PAC had just north of $307,000 in its coffers at the end of May.

According to the filing, only one member of Congress -- Rep. Charlie Gonzalez (D-Texas) -- received a $1,000 campaign contribution from the PAC last month. A Gonzalez spokeswoman said yesterday that he received the check at a fundraiser without knowing that it originated from BP, and the check was never cashed and has since been returned.

The filing does also show that several other lawmakers returned $1,000 checks from late 2009 that they say they have never cashed, including Reps. Joe Barton (R-Texas), John Shadegg (R-Ill.), Jim Costa (D-Calif.) and Bill Shuster (R-Pa.), along with Sens. Saxby Chambliss (R-Ga.) and Jon Kyl (R-Ariz.).

The PAC did make contributions of $1,000 to nine state-level candidates in California -- most of them running for Assembly or state Senate.

The May filing follows a recent pattern from the PAC. In April, the company also dolled out a total of $2,000 to two members of Congress, with both donations coming before the Deepwater Horizon drilling rig explosion, while pulling in a little more than $20,000 from its contributors.

Prior to the spill, the company handed out almost $80,000 in contributions to lawmakers during the current election cycle, according to the Center for Responsive Politics.

A BP spokesman said yesterday that the company itself has nothing to do with the PAC's operations and that it is run independently by company employees. "We BP don't control the PAC, run by staff members under a committee," said BP spokesman David Nicholas. "BP's corporate policy is not to make political contributions anywhere in the world."

It is standard practice for industry PACs to be identified as representing a separate voice of company employees, though some of the biggest PAC donors also often tend to be high-ranking company officials.

BP's campaign contributions have also become a major political weapon in recent weeks, in particular for environmental groups looking to put pressure on Republican and some moderate Democratic lawmakers. They have been mentioned in ads run against Sen. Blanche Lincoln (D-Ark.) during her primary election and in other ad campaigns designed to build momentum for climate and energy legislation.