Detectives on Monday arrested a suspect in the murder of two Swiss nationals in Kiembeni, Mombasa.
The bodies of Werner Borner Paul, 70, and Marriane Hornel were found in the area by pedestrians on Sunday morning.
Area police chief Christopher Rotich said they were wrapped in blankets.
Third suspect Geofrey Mwari was found in Kisauni on Monday and is being grilled before court once investigations are completed.
Regarding the investigation, regional police commander Larry Kieng' said "no one can kill and hide".
"We have ways to capture and detain suspects even if they camouflage," he said, adding they took all items found at the scene for use in tracing the suspects.
Rotich told Reuters by telephone that the two victims suffered severe injuries.
"One has deep cuts on the head and it seems they were killed using sharp and blunt objects."
Police earlier took the caretaker of the property where the couple was to stay for questioning. The caretaker had gone to pick the couple from the airport.
In an interview with Reuters, Kieng said: "They were expected to arrive by midnight but something happened between the airport and the home. We have found some evidence from a saloon car which was parked at the residence."
In 2014, Russian and German tourists were robbed and murdered in Mombasa in two separate incidents. Police later shot dead two suspects they said had been behind the murders.