Why didn't S.H.I.E.L.D. intervene during the events of The Incredible Hulk?

Question

During the events of The Incredible Hulk, General Ross is pursuing Bruce Banner all over the world and triggering 'events' of the Hulk emerging.

Is there an MCU explanation of why S.H.I.E.L.D. were not involved in attempting to capture the Hulk along with General Ross?

I'd assume they would either be aiding or opposing the capture, rather than just not being involved. Whilst Ross had personal experience with Bruce, S.H.I.E.L.D. had much more expertise with supernatural phenomena. They had been dealing with it since the 40's.

In The Avengers Black Widow says that S.H.I.E.L.D. had been keeping tabs on Bruce. Even if they didn't know his whereabouts themselves before The Incredible Hulk, it shows they were at least interested in him. Did they only learn of his existence after the events of the movie?

Or when General Ross found out that Bruce was in Brazil, did he essentially go rogue in pursuing Bruce Banner, so that S.H.I.E.L.D. wouldn't find out what he was up to?

Answer 1

This is roundabout touched upon during the third issue of Fury's Big Week.

SHIELD is monitoring Banner, as Natasha immediately calls Fury when the fight breaks out on the college campus. Fury specifically tells her to prevent Ross from acquiring Banner.

We're not given any further information, but the fact that Fury wants to keep Banner out of Ross's hands indicates that they don't want to help capture him.