Daily Kos, the liberal website, has ended its relationship with pollster Research 2000 after independent statisticians raised questions about polling results. Markos Moulitsas, the Daily Kos founder, said today that he no longer had confidence in any of the Research 2000 work, which includes a poll on the May special election for Congress in urban Honolulu’s 1st Congressional District.

From a post by Moulitsas:

While the investigation didn’t look at all of Research 2000 polling conducted for us, fact is I no longer have any confidence in any  of it, and neither should anyone else. I ask that all poll tracking sites remove any Research 2000 polls commissioned by us from their databases. I hereby renounce any post we’ve written based exclusively on Research 2000 polling.

In an April poll, Research 2000 had the special election for Congress a statistical dead heat, with Charles Djou — the eventual winner — at 32 percent, former congressman Ed Case at 29 percent and state Senate President Colleen Hanabusa at 28 percent. Seven percent were undecided.

Daily Kos was sympathetic to Hanabusa — who would finish second — and described Case as a “Lieberdem,” a derisive reference to U.S. Sen. Joseph Lieberman, a Connecticut independent.