Question

three thieves have been caught change into active voice ​

Answer 1

Answer:

$\huge \star \mathtt \red{ Answer\::} \star$

Police has caught three thieves

Explanation:

Basically when we make sentence from passive to active we use "Someone" but here is thief and thiefs are only caught y "Police".

Answer 2

$\huge\star\mathtt\red{Answer}\star$

They have caught three thieves.