Chief operating officer (Otago) Vivian Blake said the temporary solution had been agreed while "we work through the whole of staffing issues".
The extra cover would be from 1pm to 11pm at weekends.
This move had been discussed with the Resident Doctors Association as well as the consultants and resident doctors in the emergency department who "I believe appreciate the need to look at the level and skill mix of all staff in the ED".
Earlier this month clinical leader Dr Tim Kerruish said consultants shared concerns raised by the junior doctors about staffing levels and proposed night shift roster changes.
Last year extra nursing staffing was introduced following nurses' concerns about their workload.
The hospital has been under pressure to shorten the length of time patients stay in the department.
It has been languishing near the bottom of national tables on the requirement that 95% of patients stay no longer than six hours in an emergency department.
Work is continuing on a draft proposal for the establishment of a short stay unit in the department, designed to cater better for those patients who might need to spend several hours in the department but not necessarily need admitting to a ward.
Mrs Blake said it was not likely to go before the board until its June meeting.
A current advertisement for a 0.4 full-time equivalent consultant in the department was not an extra position, but one to cover a staff member returning from maternity leave and wanting to reduce her hours.
