As pay raises go, it was both big and small. A 15.4 percent bump is nice. But it only added up to $4,704 per year.

That raise put just $268.66 more in the pocket of Alex Clark, a trades helper at the Office of the Philadelphia City Commissioners, before it was rescinded 12 days later in October 2013.

But that small chunk of change may add up to big trouble for his brother - and boss - Commissioners Chairman Anthony Clark.

The executive director of the Philadelphia Board of Ethics in January accused Clark of pushing for his brother's raise and then threatening the commissioners' budget officer for cooperating with an investigation.

The public would probably not know that, since the board keeps investigations and accusations confidential until they are voted on - except that Clark, trying to head off four counts of violating the city code on conflict of interest and retaliation, sued the board last week.

Clark claims that Shane Creamer, the board's executive director, "does not have the authority" to "pursue and/or prosecute" the case. And he attached to his lawsuit the board's 13-page "notice of administrative enforcement proceedings."

In that Jan. 22 notice, Creamer made these allegations, while recommending that the Board of Ethics fine Clark a total of $8,000:

Clark asked his deputy in September 2013 to come up with a way to increase his brother's pay.

The deputy spoke to a human resources manager, who in October increased Alex Clark's pay rate to Clerical Supervisor II, though he never did the work done by someone with that title.

Commission staffers soon decided the raise should be stopped.

The three elected city commissioners then discussed the raise in executive session, and agreed to have their top attorney look into it.

Someone filed a complaint in November 2013 with the Board of Ethics enforcement staff, which started an investigation.

Valerie Crawford-Keith, the commissioners' budget officer, who was involved in discussions about the raise, was then told by Alex Clark that his brother "wanted to tell her what she should and shouldn't say to the board enforcement staff when she met with them."

During a January 2014 meeting, Anthony Clark told Crawford-Keith that "the 2014 elections were coming and stated that he was planning to get reelected. He said to Ms. Crawford-Keith that, given potential changes to the commission, it would be good to 'have someone on your side.' He also told her, even though she is a civil service employee, 'that doesn't mean nothing can happen to you.' "

Clark's lawsuit hinges on a technical question: Can Creamer initiate investigations on his own?

The Board of Ethics, like other public regulatory agencies in Pennsylvania, has staffers who conduct investigations, and a board that rules on the merits of allegations.

Jimmie Moore, Clark's attorney, said that division is not strong enough to protect the constitutional rights of those being investigated.

"That wall is too thin," said Moore, a former Municipal Court judge.

Efforts to reach Clark, first elected in 2007, were not successful.

An attorney for the Board of Ethics did not respond to a request for comment. Creamer's attorney declined to comment on the lawsuit.

Commission records show base pay for Alex Clark, who has worked for the agency since 2008, was briefly increased from $30,584 to $35,288 per year in 2013.

His brother, paid $134,149 per year as chairman, drew attention in October when Philadelphia City Paper revealed that he had not voted in the five previous elections. The city commissioners oversee elections.

Clark shrugged that off as a private matter. He was endorsed in his bid for a third term by the Democratic City Committee for the May 19 primary election and finished with a commanding first-place victory with 75,031 votes, despite doing little campaigning.

215-854-5973@byChrisBrennan