Police say Jack Parfitt hasn't been seen for nine days.
Reward put up after sexual assaults
A reward of up to £5,000 is now being offered for information leading to the arrest and conviction of whoever is responsible for three sexual assaults in the county.
The reward is being offered by the independent charity Crimestoppers.
The officer leading the investigation, DCI Alastair Stenner, said he hoped the reward would encourage people to come forward with information.
He said: ''These incidents have been extremely traumatic for the victims and clearly the person or people responsible need to be caught before they attack someone else.
''Ive been conducting a painstaking investigation for a number of weeks now, but I still believe somebody somewhere knows who did this and I hope they may be encouraged, perhaps by the reward, to come forward and help us.
''The appeal might also jog people's memories and something that had not seemed relevant until now might suddenly seem so.
''I'd urge everyone in the county to get in touch immediately if they can help us find the person or people who have carried out these attacks.''
The reward will only be available to anyone providing information to Crimestoppers, leading to the arrest and conviction of any person or persons linked to the three incidents.
Crimestoppers can be contacted on 0800 555 111 and also via the Crimestoppers website .
Callers ringing Crimestoppers can remain anonymous, and this does not prevent them from claiming the reward.
A team of detectives has been assembled to investigate the three sexual offences which have taken place in the past six months.
While they are not being formally linked, all three cases are being examined together due to the similarities between the crimes.
The three crimes being investigated under Operation Abbeymead are:
On Wednesday November 30 2011 at around 8.25pm an 18-year-old local woman was grabbed by a man as she walked through Welch Road playing fields, in the Hester's Way area of Cheltenham. He dragged her to an area of the park and then sexually assaulted her. It is believed that a balaclava was worn by the offender.
At around 6.45pm on Thursday January 19 2012 a 16-year-old Gloucester girl was walking across the footbridge from Penrose Road to Evergreen Walk, which crosses the A40, at Innsworth when she was approached by a man. The man threatened, assaulted and indecently assaulted the girl, and stole her mobile phone. It is believed that a balaclava was worn by the offender.
On Wednesday May 2, at around 10.30pm, a 20-year-old woman was attacked as she walked along a grassed area behind The Clock Tower, near West Lodge Drive, in the Coney Hill area of Gloucester. The offender tried to grab the woman's handbag before pushing her to the ground and carrying out the serious sexual assault. He ran off in the direction of The Clock Tower.
Two men from the Gloucester area have been arrested during the course of the investigation and are on police bail.
Enquiries are continuing and information from the public remains important to the enquiry.
More local news ...
Advice to keep cool as the temperature rises
Check out plans for a futuristic looking new bus station for the city
Stroud District Council make legal challenge against Government decision
Recently Played Tracks
On Radio: Justin Walker
6am - 10am
Text 'SHOW' to 82122
Discover this season's unmissable TV like Yonderland, and win Sky TV free for a year
Get a 200% Welcome Bonus. Deposit £10, get £30 to play! T&C's apply.
Find your local four day weather report here.
What's happening on the roads where you are?
Make Heart the soundtrack to your day and you could be a winner with great prizes up for grabs throughout the day.
Find out more about some of the companies advertising on Heart.
Get some great ideas on how to advertise your business on radio, online and on mobile.