Today's statement from Lincs Police says:
Late yesterday evening a third arrest was made in connection with this murder enquiry. A 37-year-old male from the Peterborough area was arrested on suspicion of an offence of assisting an offender. He has been detained at Spalding police station for questioning by detectives.
The 54-year-old local man, who was arrested at a French port at approximately 12.30pm on Monday afternoon is continuing to be questioned by police at Lincoln Police Station.
The 26-year-old female from the Peterborough area, who was arrested on Monday evening on suspicion of an offence of assisting an offender, has been released on police bail pending further enquiries. She is due to return to Spalding Police Station in 4 weeks.