Mr Robertson said the milk was the same product with different labels.
"Ruimu had their products denied to get in at exactly the same time as Oravida had their products allowed as shown by the import clearance certificate," Mr Robertson said.
"Evidence is building of a correlation between the Minister's October dinner with a Chinese border control official in Beijing and later visit to Oravida's Shanghai office, and her husband's company's export issues disappearing.
"Judith Collins' intervention was designed to benefit Oravida. The public can join the dots; the Prime Minister now needs to do the same."
Prime Minister John Key this morning said Mr Peters' claims about Oravida's import clearance certificate - which the NZ First Leader also linked to the company's $30,000 donation to the National Party a few days after it was posted on its website - lacked substance.
"It's typical Winston Peters isn't it. Try and put out a couple of dots and see if people will join them, say it a hushed tone to make it sound more sinister. The advice I've had from MPI is it's a stock standard certificate."
Oravida has so far not responded to the Herald's requests for comment on the saga.
Three of Question Time's 12 questions this afternoon were directed at Ms Collins over the Oravida affair while Green Co-leader's question to Prime Minister John Key about "his confidence in all his ministers" appeared likely to target her as well.
Ms Collins has consistently maintained that Oravida's business was not discussed when she met the unnamed Chinese border control official at what she says was "a private" dinner. The Beijing dinner was also described as a private event in MFAT documents about her trip released last week.