A woman is in custody on suspicion of assaulting an emergency worker after police responded to reports of a disturbance in Barry on Saturday, 8 August.
Video footage has emerged showing the use of a taser during the arrest.
South Wales Police have defended it's use and say their officers "do not deserve to be assaulted."
Officers were called to an address on Main Street shortly after 5pm and the taser was discharged after two people "failed to comply with instructions".
Sergeant Richard Lloyd at Barry Police Station said: “Our officers work tirelessly to protect the communities they serve and they do not deserve to be assaulted during the course of that duty.A 35-year-old man has also been arrested, on suspicion of using threatening or abusive words or behaviour. Both are currently in custody.