Sutherland Shire Police Local Area Command is continuing its search for a man thought to be missing in the Royal National Park.
Police said the search for Christopher Deep, 36, commenced on Saturday and continued throughout Sunday and Monday.
It will resume again tomorrow.
Mr Deep, of Sydney's Inner West, has not been seen since last Tuesday, February 23.
He was reported missing to Inner West Police Local Area Command last Friday, February 26.
His family and police hold significant concerns for his safety.
Police believe Mr Deep drove to Loftus railway station last Tuesday. CCTV captured him with his bike at about 12.25pm. It is thought he might have been planning to ride his bike in nearby bushland.
Sutherland Shire Police have been assisted in their search efforts by the State Emergency Services, NSW Rural Fire Service, Royal National Parks officers, NSW Police Rescue, Pol-Air and the Mounted Police unit.
He is described as of Caucasian appearance, 180-185 centimetres tall, 70-75 kilograms, slim build, fair complexion, with short brown hair and brown eyes.
He was last seen wearing a grey shirt, dark shorts, grey sneakers and a blue bike helmet. He was also carrying a backpack.
Anyone with information on his whereabouts is urged to call police or Crime Stoppers on 1800 333 000 or click here.