There are two common forms that use the passive voice in English.
Here is an example of each:
He is believed to have stolen the painting.
It is believed that he stole the painting.
Neither of theses forms translate well directly into other languages. In many other languages the impersonal form is used rather than the passive.
Here are some examples of verbs which are commonly used with these passive forms:
Subject + Passive (to be + participle) + Infinitive
He is believed to be in Russia.
In this form we use:
If we want to use this form to talk about the past, use the auxiliary verb “to have” (“haber”, not “tener”):
“He is believed to have left the country.”
This form is much easier, it simply uses;
It + Passive form (to be + participle) + that + clause
“It is believed that he has left the country.”