A device exploded on the Duncrue path close to Hazelbank on Saturday 9 March, during a security alert that closed part of the M5 for almost 24 hours.
Three officers, one of whom was a woman, were on the towpath when the bomb exploded.
Senior police chiefs said the attack was designed to kill police.
A 39-year-old man is being questioned by PSNI Serious Crime Branch detectives investigating the attempted murder of the three officers.
He was detained in Belfast on Thursday morning.