Lib Dem candidate Jenny Willott (top) and Welsh party leader Kirsty Williams are both pictured apparently speaking to a police officer - but he is not one
Welsh Liberal Democrats have been criticised by rivals for using a series of staged photographs with models posing as nurses and a police officer.
Leader Kirsty Williams and candidate Jenny Willott appear in near-identical pictures with someone dressed as a Pc.
Two candidates also posed for pictures with women in nurses' uniforms.
The Lib Dems said they were purely illustrative and it was "obviously difficult" for serving NHS workers and police to appear on leaflets.
But other parties accused Lib Dems of trying to mislead voters.
Ms Williams appears in the Welsh party manifesto with a "model" dressed as a police officer.
It later emerged that Ms Willott, the Cardiff Central candidate, poses with the same man in a similar location looking towards Cardiff Castle in an election leaflet.
Last Friday it was revealed that Cardiff North candidate John Dixon's leaflet showed him talking to a woman in a nurse's uniform who was actually a researcher for Lib Dem Assembly Member Mick Bates.
This leaflet picture showed Lib Dem candidate John Dixon speaking to a researcher dressed as a nurse
Bridgend candidate Wayne Morgan's leaflet also features a photograph of himself with someone in a nurse's uniform, and the party called her a "model".
The photograph with Ms Williams appeared on page 35 of their general election manifesto in a section promising more officers on the beat.
A Lib Dem spokesperson said: "Photos like these are used for illustrative purposes as it is obviously difficult for some serving members of the police force or the health service to appear in general election literature."
The party said that the use of such "illustrative photographs" was strictly limited to the policy areas of health and policing.
The spokesperson said: "In our election communication, we only used illustrative photographs to highlight our commitment to improving the NHS and increasing the number of police on our streets."
The party stressed that Ms Williams was not "complicit in the impersonation of a police officer".
The spokesperson said: "There has been no such impersonation. Being photographed dressed in a way that illustrates the police service, does not in any way represent impersonating a police officer, so there is nothing to be complicit in."
The party was unable to confirm how many candidates may have posed with this kind of "model."
However, a Welsh Conservative Party spokesperson said: "We were under the impression impersonating a police officer is a criminal offence."
He added: "It would seem the Lib Dems' support for law and order is purely 'illustrative' - just as it was last week when they used a fake nurse to promote their claims of support for the NHS.
"The Liberals talk about being an 'honest partner' at this election. Yet twice in three days they've been caught out trying to mislead the public."
The Tories said they were not aware of any such examples in their own election literature, and that each election publication was the responsibility of each election agent.
A Plaid Cymru spokesman said: "We can confirm that we don't dress up members of staff or supporters in uniforms to pretend that we're talking to real policemen or nurses - we prefer to talk to the real thing."
Plaid also told BBC Wales: "It's pretty worrying that the Lib Dems' leader appears to be getting advice on law and order from and actor or member of staff dressed up as a policeman, however we're not surprised by this latest leaflet - everyone knows that the Lib Dems are a party willing to do just about anything to get votes."
"They have also tried to dress Nick Clegg up as someone who cares about Wales - and clearly that's not true."
A spokesperson for Welsh Labour said: "First a fake nurse, then a fake policeman - what's next, a picture with Fireman Sam?
"Everyone knows that the Lib Dems will do absolutely anything for a vote, from their dodgy graphs to make-believe photos, they have always been the shameless chancers of Welsh politics."
The Lib Dems said they would not reveal the identity of the stand-in police officer.
"We don't intend to divulge the identity of the model for obvious reasons as it would potentially cause a lot of media intrusion for the individual concerned and is not material to the issue," the party spokesperson said.