The correct answers are The luxurious yacht is said to be being monitored by the paparazzi. and The controversial photos are alleged to have been leaked by an insider.

Reporting verbs like say and allege easily form double passives, even with complex continuous ("to be being monitored") or perfect ("to have been leaked") passive infinitives.

However, verbs of decision or agreement (like decide, agree, propose) cannot take this structure. "Was agreed to be broadcast" is an invalid double passive. You must use a that-clause instead: "It was agreed that the interview would be broadcast" or "It was decided to postpone the wedding."