David O'Sullivan's family have not heard from him since early April
An investigation has been launched into the disappearance of an Irish man in California.
David O'Sullivan (25) has not been seen since early April.
It is understood he set off to hike the Pacific Crest Trail in late March - a route which takes around five months to complete.
However, he has failed to make contact with friends and family in recent months.
Mr O'Sullivan is said to have arrived in Idylwild, California on April 5th, and emailed his parents two days later.
In a statement posted on Facebook, his family explain: "This was our last contact with him. We knew that weeks might pass without contact but no more than 2/3. After 3.5 weeks, we took to Facebook and asked if anyone had met him on the trail."
Despite receiving support and assistance from hikers, there was no positive sighting of David.
On May 31st, the family got in touch with police here in Ireland, and they received information that David's bank account had recently been active.
They said: "While not happy, this satisfied us that he was OK, spending money on food, etc and that he was simply unable to charge his tablet or get WiFi access. We waited for an email from him."
After his family contacted Gardaí again a month later, David has been reported as a missing person to American, Irish and international agencies.
The Department of Foreign Affairs says it is aware of the case and is providing consular assistance.