Members of the Unite union are calling for an investigation into allegations that officials handed information to the operator of a construction blacklist

In a letter seen by Building, two members have requested an independent inquiry into whether members of the Amicus section supplied personal data to Ian Kerr, who led the consulting association. Kerr operated the illegal blacklist that was revealed in March to have been used by more than 40 construction firms.

Last Thursday, whistleblower Alan Wainwright published a series of letters online that informed Derek Simpson, joint general secretary of Unite, of the blacklist’s existence. The first is dated June 2006.

Kerr pleaded guilty to breaching data protection laws on Wednesday and was referred to the High Court for sentencing.