A Brisbane family says they were left shocked and outraged when a security guard on Moreton Island tried to force them off a public beach, claiming nearby Tangalooma Resort held exclusive rights to the area.

The security guard was acting at the behest of resort management, but the resort is built on crown land and the Department of Natural Resources, Mines, and Energy confirmed the beachfront is public space.

Lisa Wilkins told the ABC she was swimming in front of the resort with her partner and eight-year-old daughter on Good Friday in late March when they were approached by a security guard.

She said she was "flabbergasted" by what they were told.

"He called us out of the water to come over to him and he said: 'You can't swim here, and you can't be on this beach, it's a private beach and you can't moor your vessel there'," she said.

"We said, 'we're just swimming, it's low water — you can go away'.

"And he said, 'well don't go anywhere up near the resort'.

"I said, 'well we're not moving our boat and we're not stopping swimming. Goodbye. Leave us alone'.

"He ended up going about five metres away from us and sitting there for a while, making sure that we were knowing that he wouldn't be leaving us alone."

People are able to walk across the stretch of the beach in front of the resort. ( ABC News: Ashleigh Stevenson )

Ms Wilkins said they finished swimming and eventually left.

"We were being belittled in front of our child for a public right to be able just to swim," she said.

When she complained to Tangalooma Island Resort, head office replied in an email apologising if Ms Wilkins felt she was disrespected but that security guards are able to move on beach goers if they are not staying at the resort or have a day pass.

"To address your concerns — our security guards are within their rights to ask you to move on if you are on the beach directly in front of the resort above the low-tide mark," the email stated.

The department's map of leasehold areas clearly shows beaches are not included. ( Supplied: Department of Natural Resources and Energy )

"I understand that the main source of dissatisfaction with our resort was that it seems that you were not treated in a respectful way by our security guard ... I can assure you that senior management will be raising this incident for discussion and clarification with all of our security personnel, to ensure they are fully aware of the correct procedures, protocols and powers in their day-to-day operations."

Tangalooma Island Resort is built on crown land but is able to operate under a State Government lease managed by the Department of Natural Resources, Mines and Energy.

It also holds a 'permit to occupy' over the public beach, giving it special privileges and responsibilities to run minor operations on a public area, but this does not provide exclusive access.

When the department became aware of the incident, it issued a warning to the resort's management, reminding them the beach remains public space.

"The department is working with Tangalooma Island Resort and has reiterated to management the public's rights and obligations regarding the use of the beach in front of the resort," a department spokesperson said.

"Tangalooma Island Resort is required to allow ongoing access to this beach for the use and enjoyment of the public."

In response to questions from ABC News, Tangalooma director Brian Osborne said he was seeking urgent meetings with the State Government to clarify the resort's rights under the current arrangement.

Mr Osborne said while the resort holds exclusive rights over its own parcel of land, pedestrians will be able to transit on foot across the stretch of the beach.

"Until such time Tangalooma Island Resort receives official clarification on the terms of its permit to occupy, its representatives will not ask non-resort guests to vacate the beach directly in front of the resort property," he said.

"Tangalooma Island Resort will review all related resort policies concerning its permit to occupy the beach after all issues relating to the rights of this permit have been clarified and agreed."

Deputy Premier Jackie Trad said the State Government was looking into the leasing arrangement with the resort.

"Every Queenslander has a right to enjoy our wonderful beaches — whether they're on Tangalooma or whether they're at Coolangatta or elsewhere throughout the state," Ms Trad said.

"I don't think it's right that anyone was told to move on from Tangalooma beach."

Tangalooma Resort is built on crown land but able to operate under a Government lease. ( ABC News: Ashleigh Stevenson )

Resort says focus on 'safety and security' of guests

In a statement released today, Tangalooma Island Resort director David James said the resort's primary intention in patrolling the waterfront outside the resort was to "ensure the safety and security of the thousands of guests we host each month".

"The resort land is of course private, and for the exclusive enjoyment of our guests," Mr James said in the statement.

"Our permit allows us the right to occupy the beach and water directly in front of the property and we need to be able to control this area to ensure no harmful incidents occur.

"We operate a number of water sports on a daily basis that require high levels of precautions and safety monitoring, along with overseeing the safety hundreds of guests swimming in these waters."

Mr James said the resort allowed access to people walking across on the beach between the northern and southern boundaries of the resort.

"Since this particular incident occurred, we have received advice from the relevant government departments … that contradicts how we have been managing this," he said.

"We are working with these government bodies at present to clear up these discrepancies, so that our staff and security can act with clarity moving forward, and to continue prioritising the safety of our guests."

Mr James said the resort had apologised to Ms Wilkins on the day she raised her concerns and also offered to call her directly as well to discuss the incident.

"We assured her that senior management would raise the incident for discussion and clarification with all of our security personnel to ensure they are fully aware of the correct procedures, protocols, and powers in their day-to-day operations," he said.

Meanwhile, the resort is also expected to go to mediation with sub-lease holders who own property on the island, after a long-running dispute over servicing fees.