Joanna Dennehy, 30, also pleads guilty at Old Bailey to attempted murders of two more men

A 30-year-old woman unexpectedly admitted at the Old Bailey that she had stabbed to death three men whose bodies were found in ditches in Cambridgeshire this spring, following a dispute about rent.

Appearing in the dock in a white shirt with a star tattooed under her right eye, Joanna Dennehy, 30, admitted killing property developer Kevin Lee, 48, Lukasz Slaboszewski, 31, and John Chapman, 56, who were found with multiple stab wounds over the course of four days in March and April.

Her guilty plea took her lawyers by surprise, and they applied for time to discuss the plea with their client. But Dennahy told the judge, Mr Justice Sweeney: "I've pleaded guilty, and that's that."

Dennehy, from Peterborough, also pleaded guilty to the attempted murders of another two men, Robin Bereza and John Rogers, and admitted "preventing the lawful and decent burial" of all three murder victims.

She appeared alongside her 7ft 3in tall partner Gary Richards, 47, also known as a Gary Stretch. He denies the two attempted murders and helping Dennehy to dump the bodies.

Dennehy's lawyer Nigel Lickley QC told the court that he would have to check with his client that she did want to plead guilty, saying: "It is incumbent on us to inform the court whether the pleas will be maintained or changed … if that is possible we will inform the court on Monday."

But she interrupted the lawyer and said: "I'm not coming back down here again just to say the same stuff. It's a long way to come to say the same thing I have just said."

The body of Lee, described as a "wonderful father and husband", was discovered by a dogwalker in a ditch near the A16 in Newborough, Cambridgeshire, on 30 March with stab wounds to his chest. Police began a nationwide hunt to find Dennehy and Stretch, urging the public to look out for the striking-looking pair.

Dennehy was first arrested on 5 April. A day later, police were called by a farmer to say he had uncovered two more bodies on private land in Thorney Dyke, about 10 miles from Newborough. Lukasz Slaboszewski, a builder originally from Poland, was found with stab wounds to the heart, while John Chapman, who had served in the navy, had been stabbed in the neck and chest. In court, Dennehy admitted killing Lee and Chapman on 29 March and Slaboszewski between 19 and 29 March.

Lukasz Slaboszewski, left, and John Chapman, two of Joanna Dennehy's victims. Photograph: Cambridgeshire Constabulary/PA

During the search for the pair, locals said that Kevin Lee was the owner of a property where Stretch had been living and that there had been a dispute about rent money owed to the landlord.

The Daily Mail reported that Julie Gibbons, Stretch's ex-partner and mother of his teenage children Charlie and Garry, said before his arrest that he had been sharing a four-bedroom house with strangers. Locals said he lived in a shared house, which had been split into bedsits by Lee, with a man called John, who was in his 50s, and a younger man.After his death, Lee's family described his death as a "tragic loss". In a statement the family said: "We are devastated by Kevin's death. He was a wonderful husband, father, loving brother and son."

Two other defendants appeared at the hearing by videolink. Leslie Layton, 36, of Bifield, Orton Goldhay, pleaded not guilty to perverting the course of justice at an earlier hearing, while Robert Moore, 55, of Belvoir Way, Peterborough, denied assisting an offender.