When is a Liberal Democrat election winner not quite a Liberal Democrat election winner?

When the winner in question – as reports appear to indicate in the case of the newly elected police and crime commissioner (PCC) for North Wales – is identified on ballot papers as an independent rather than a flagbearer for a party riding particularly low in opinion polls.

But amid claims that Winston Roddick "hid" his party allegiance, as well as calls for him to step down immediately after winning the election, the barrister and former senior legal adviser to the Welsh assembly appeared to be settling into the role.

"I am a member of the Lib Dems, but this was discussed extensively during the campaign," Roddick told the Guardian. "I will not be taking the Lib Dem whip, and will act independently and impartially as PCC, as I have throughout my legal and judicial career."

A spokesperson for the Liberal Democrats, whose candidate in the bellwether Corby byelection slumped to a humiliating fourth place on the same night that Roddick emerged victorious in the North Wales PCC election, said that a member of the party running as an independent was a different case from a candidate who was running on a party ticket.

"The Liberal Democrats stood in just over half of the PCCs and that was because we wanted to give our local parties the opportunity, if they felt that the right candidate was an independent, to back them," he added.

However, Owen Smith, a Welsh Labour MP and the Shadow Secretary of State for Wales, tweeted on Friday night: "Winston Roddick must explain why he hid his party allegiance from the North Wales electorate. #Independent?"

Another Labour MP, John Mann, tweeted that "roddick should resign as police commissioner of he is a lib dem member."

Roddick was publicly endorsed during the campaign by Kirsty Williams, the Liberal Democrat leader in Wales, who said that the party was not putting up candidates but that she was backing him "because, as an independent candidate, he is free from party political pressure."

One of Wales's leading barristers and Wales's first counsel general, the QC began his career as a police constable in Liverpool before becoming a barrister and has been a crown court recorder.

In his campaign, Roddick said the police commissioner needed to act independently of political interference.