Lasswade Centre was evacuated last Friday afternoon when gas was detected at the £37 million joint sports facility and high school.
After an hour the centre was re-opened, when the source of the gas leak was found to be open gas taps in one of the Science classrooms. Midlothian Council has promised to launch an investigation through its health and safety department
A Midlothian Council spokesman said: “Health and Safety are co-ordinating an investigation into the situation that occurred at the Lasswade Centre on Friday afternoon.
“The Lasswade Centre was evacuated for an hour while a thorough investigation into a gas leak was carried out.
“The source was identified as being open gas taps in one of the vacant Science Labs classrooms and the situation was then resolved.
“There are no Health and Safety concerns regarding any ruptured gas pipelines at the Lasswade Centre and we await the conclusion from the investigation.”
Since opening in 2013, the community hub has suffered a number of maintenance issues including leaks and problems with the jacuzzi.