An “amorous couple in a stairwell” has been blamed for causing a flood in Melbourne’s city rail loop last week, which forced the evacuation of two stations and significant delays for people travelling home from an Olivia Rodrigo concert. Melbourne Central and Flagstaff stations had to be evacuated late on Thursday evening, causing delays across the metropolitan rail network. While it was initially believed the incident was an act of vandalism, the Victorian transport infrastructure minister, Danny Pearson, said a review of CCTV by Metro Trains had proved otherwise. Sign up for Guardian Australia’s breaking news email “It would appear that an amorous couple in a stairwell dislodged a sprinkler,” Pearson told reporters outside parliament on Wednesday. “There was extensive flooding. Metro will be investigating these matters further and police are investigating. “Perhaps a stairwell may not be an appropriate place to find yourself in after dinner.” Police on Tuesday released images of a man and woman who they said may be able to assist with their investigation into the incident of “criminal damage”. They said a duo had gained access to a stairwell connecting platforms at Melbourne Central train station about 10.40pm, and damaged a water pipe and fire sprinkler. On Friday, police said the damage caused extensive flooding to several platforms, which resulted in an automated evacuation of both stations and significant delays, including for commuters returning home from Rodrigo’s concert at Rod Laver Arena. “At this stage it is unclear if Miss Rodrigo planned to get home via train or limousine,” they said at the time.