The reward for information leading to the recovery of Nicola Payne's body has been raised to £100,000.
The young mother from Coventry went missing more than 26 years ago, when she was just 18.
She was last seen alive on a path in the Henley Green area of the city in December 1991.
Her family believe her remains are hidden. In December last year, they had raised the reward to £30,000, and it's now gone up again.
In recent days, specialist search teams have been working in Coombe Abbey Country Park, though police say it was due to a review of previous work, not any new information.