Why present perfect

Hello.
In this sentence “…a rumour which started after a flying sauser was said to have crashed in New Mexico in 1947”. Why do we use Present Persect?

This isn’t a present perfect as such but in fact a perfect infinitive.

Oh, yes, definitely, sorry, it’s a bit late so I can’t formulate my questions properly. I can’t get why we use PP infinitive here.

The flying saucer crashed in 1947 - that’s why it’s perfect and not present infinitive.

omg, I’m sorry, I still can’t understand the rule.=( Is it because “to have crashed” happened before “was said”? That’s my only idea.

Hi, this usage was very confusing to me too - this website seems to have a pretty clear explanation: grammaring.com/reporting-an- … sive-voice

If the reported action happens earlier than the reporting itself, we use perfect or perfect continuous infinitives.

He is believed never to have smiled at anyone. (= They believe he (has) never smiled at anyone.)

She is known to have been writing songs for years. (= They know she has been writing/was writing songs for years.)

Lucy was assumed to have left the day before. (= They assumed Lucy had left the day before.)

The organisers were thought to have been preparing for days. (= Everybody thought the organisers had been preparing for days.)

This painting is known to have been painted by Caspar David Friedrich. (= They know that the painting was painted by Caspar David Friedrich. / They know that Caspar David Friedrich painted it.)

America was thought to have been discovered by Columbus. (= People thought that America had been discovered by Colombus. / People thought that Columbus had discovered America.)

If the reporting and the reported action happen at the same time, we use simple or continuous infinitives.

This football coach is said to be strict but fair. (= They say this football coach is strict but fair.)

Vincent is thought to be living in Paris at the moment. (= They think Vincent is living in Paris at the moment.)

Paul was thought to be in the house. (= They thought Paul was in the house.)

Vincent was thought to be staying in Paris at that time. (= They thought Vincent was staying in Paris at that time.)

This painting is believed to be owned by Mr Wilkins. (= They believe the painting is owned by Mr Wilkins. / They believe Mr Wilkins owns the painting.)

The axe was believed to be made of mithril. (= The dwarves believed that the axe was made of mithril.)

Oh, thank you, this I can understand.=)