Students are being advised not to rely on the Ministry of Education's figures about how much graduate health workers can earn.
The Ministry has posted on its website how much graduates in different fields can earn as a way of assisting students decide what courses to take.
But Peter Gene, president of APEX, the union representing Allied Scientific and Technical Health Practitioners, is disputing the figures.
He says second year medical radiation technologists can expect to receive a 40-hour per-week base salary of $52,000, nearly $7,000 less than the figure on the website.
"Well they probably need to look beyond the website I would say, and really investigate the matter carefully as to what the pay scales are for those jobs."