Hundreds of volunteers have joined a search looking for missing teenager Gaia Pope.
Search parties scoured areas around Swanage near to where the 19-year-old was last seen 11 days ago.
Ms Pope's father, Richard Sutherland, joined volunteers and thanked them for their efforts on Saturday.
Police have launched a murder investigation as they piece together Ms Pope's movements.
The search comes after investigators arrested and released a 49-year-old man, the third such person after a 19-year-old man and 71-year-old woman were detained before being let go.
On Thursday clothes belonging to Ms Pope were found on open land south of Swanage near some cliffs.
Thanking volunteers for their help on Saturday, Mr Sutherland said at Durlston Country Park: "I just want to say a massive thank you for coming out. It is very heart warming and the support gives us a lot of hope."
The mass searches were organised by the Find Gaia group on Facebook.
On Friday, the teenager's mother said that she believed "miracles can happen" as she urged people to keep looking.
The last reported sighting of Gaia was at an address in Manor Gardens in Morrison Road, Swanage, at around 4pm on November 7. She was wearing a red checked shirt with white buttons, grey and white woven leggings and white trainers.