Robert Lines

Bob Lines was a policeman. As a sergeant in Smallmarshes, he filled in the Third Doctor on the disappearance of Marc Marshall and the emotional state in which they found Barbara Redworth. However, he would not let the Doctor see the cottage where Redworth was found until the following morning. (PROSE: The Scales of Injustice)

Some time after becoming a detective inspector for the Brighton CID, the Sixth Doctor helped him to thwart the Master's attempt to hack into Dow-Jones and Fort Knox. In return, he aided the Doctor's fight against SenéNet. (PROSE: Business Unusual)

Later, he met with Melanie Bush when she returned to Earth after her years of travel with the Doctor. He listened to her describe her experiences, then assured her that her parents missed her and would be "overjoyed" that she was home. He offered to take her home. (PROSE: Missing, Part One: Business as Usual)

Two years after Mel returned, Bob Lines retired from the police. On his retirement day, Trey Korte came, seeking safety from the Magnate. When Trey fell into a self-induced coma, Lines contacted the Doctor. (PROSE: Instruments of Darkness)

A version of Lines, known as Praetor Linus, existed in an alternate timeline where the Roman Empire never fell. He was stationed in Sussex and knew that timeline's Sixth Doctor. (PROSE: Spiral Scratch)