Police say David Alun Lewis lived with his parents in Ystrad Mynach, but would sometimes visit Cardiff and stay at the Huggard Centre.
His parents have paid tribute to him:
This is so sad. We love David so much and our lives will never be the same again.
We can’t believe such a thing has happened to our son.
The last known sighting of Mr Lewis was around 7.45pm on Wednesday walking along Penarth Road near the Big Yellow Storage opposite a BMW garage.
Police are still appealing for witnesses, and say they want to speak to anyone who was near the Taff Embankment between 7.45pm and 11.45pm on Wednesday.
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