Police in Zambia have been banned from marrying foreigners, according to a memo by police inspector general Kakoma Kanganja circulating on social media.
The memo, dated 11 January, said those who were already married to foreigners should declare this within a week.
It said failure to do so would "attract disciplinary action".
Police spokeswoman Esther Katongo said: "Issues of security are delicate. If not careful, spouses can be spies and can sell the security of the country."
Ms Katongo told the BBC that a standing order had been issued, notifying police officers of the measure, but that the ban itself was not new.
She said officers had previously obeyed the ban but the new order had been thought necessary because some police had begun ignoring it.
"There are a few officers who have started marrying foreigners," she said. "They are ignoring the previous requirement and this is why another standing order has been passed to remind officers what they are supposed to do and not supposed to do."
She said it was likely officers who had married foreigners would now be given "some rules they should follow".
Asked why such measures were necessary, Ms Katongo said: "When you get married, they say that you are one. You know what marriage is - you share secrets. And you can tell officers 'do not disclose' but you have no control. You won't be in their homes to always check on them.
"The security of the nation is what is paramount."