The 27-year-old man was held at his home in Dulwich, south London, on suspicion of bestiality with sheep. He was also wanted in connection of the possession of drugs with intent to supply.
Detectives said the arrest followed allegations made to them in May and June.
"Two male joggers said they had observed a man molesting the sheep in a field at Botany Bay Lane, Chislehurst," police said in a statement.
"A similar incident was reported to police by a stables employee in the area."
Media reports said the man had been barred from visiting farmland while officers carried out their investigation.
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