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Yesterday, LL noted and WAMU’s Patrick Madden detailed that Councilmember Vincent Orange‘s campaign last year accepted several thousand dollars worth of donations in the form of $1,000 money orders, according to his campaign records. Most of the money orders came from people or businesses with ties to Jeff Thompson, the contractor and donor whose home and offices were raided last week by federal law enforcement authorities.

There is, of course, nothing illegal about accepting campaign contributions in the form of money orders. But their prevalence in donations linked to Thompson raises plenty of eyebrows because 1) they are a rare form of payment in most campaign finance reports, especially in large amounts like $1,000 and 2) the Washington Post detailed last year how Mayor Vince Gray‘s campaign had the unusual habit of converting cash donations into money orders to circumvent the $25 limit on cash donations. The Post has already noted that the Thompson network of donors appears to have given money orders to the Gray campaign.

A look at campaign finance reports of Thompson-backed candidates in recent races shows that money orders were a common practice. Last summer, LL counted $13,000 worth of donations from the Thompson network to Ward 6 challenger Kelvin Robinson‘s 2010 unsuccessful campaign and $6,000 to Jeff Smith, who lost the Ward 1 race that same year.

The first campaign finance report of Robinson shows 12 different money order donations, all at the $500 maximum limit, all given on the same date. Four of those money orders come from LLCs owned by Thompson. Robinson, who was former Mayor Anthony Williams‘ chief of staff, says he sees nothing odds with the money orders he received from Thompson.

“It’s an acceptable form of campaign contributions,” he says. “I don’t know why there were so many.”

Robinson says he didn’t witness any donor give his campaign money orders. He says Thompson threw him a fundraiser at his accounting firm and was responsible for rounding up the donations.

“He handled the fundraising portion of it,” says Robinson, who noted that the donors at the fundraiser also gave through checks and credit cards.

The first campaign finance report of Smith, who lost to Ward 1 Councilmember Jim Graham in 2010, reports 30 money orders at the $500 maximum amount. Several of Thompson’s companies are listed as having given money orders, as well as Carrietta Butts, a Georgia resident who has never lived in the District. She told LL last year that she’s an old friend of Thompson’s. Smith didn’t immediately return a call seeking comment today.

Again, LL feels the need to point out that there’s nothing improper about receiving money orders as campaign payments. But the fact that there are so many money orders tied to Thompson is worth pointing out as the federal investigation into Gray’s campaign heats up.

Photo via U.S. Postal Service