A 41-year-old man detained last week in connection with the abduction of two schoolboys, 11, was released on Monday without being charged.
The man, who works as a nurse, is suspected of attempting to convince a doctor to lie to police that he had been treating the main suspect, 35, in the case.
He is also suspected of illegally providing the 35-year-old with sedatives that were used to subdue the two boys.
The 41-year-old was arrested on Friday.
The suspected kidnapper was arrested at his flat in the Kamares area around seven hours after the boys went missing from school early on Tuesday. He said he had planned to hold the boys to ransom.
The kidnapper pretended to be a new teacher at the school and asked a group of boys for help to carry some books. The two boys, who are friends, volunteered.
The boys were found unharmed but dazed and confused. It later emerged that they had been given sedatives in lemonade to keep them quiet.
On Saturday, police said they had finished examining a computer found at the 35-year-old’s flat but did not find anything incriminating.