Members of the public and police officers continued the major search for the 79-year-old overnight.
Mr Collins was last seen at an address in Blomfield Drive, Chichester on Saturday at around 3pm and people have been searching Oaklands Park and other areas of the city in the hope of finding him.
Missing Persons Coordinator Sergeant Ian Maloney said: “We are concerned about Leslie because he recently suffered a stroke and this is out of character for him.
“Please contact us if you have any information which can help us find him and make sure he is ok.”
He is described as white, 5’ 4” and of medium build with short white hair. He was last seen wearing mustard coloured trousers with a beige cardigan and a dressing gown.
If you see Leslie or have any information about his whereabouts police have asked people to email [email protected] or call 101 quoting serial 914 of 23/ 01.
If he is in danger or in need of urgent medical attention please call 999 immediately.
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